[Graybeard]

Dear Rascal ...

Perhaps you can help me here. And after all, what I am about to ask can be considered relative to this thread, as they display opposites.

In my blog perhaps you saw 'Space, Time & Einstein' by Paul R. Heyl. There is a section there that really puzzles me. This refers to the more 'mystical' aspect of Einsteins Theory.

If I should accelerate away from you rapidly, then time slows for me, in relation to you, the person being left behind.

But you could consider, rightly so, that you are accelerating away from me, then time is slowing for you ... in relation to me the person being left behind.

Therefore the other persons clock is always slower according to the observer. If we meet again our apparent time dilations will cancel out and things will appear normal.

Is this correct ..... or:

Is there a measurable difference in both our accelerations against the background of 'Spacetime' and one of us is really accelerating faster than the other.. the one experiencing the greater mass increase ... in which case a real and permanent time dilation is occurring so that should we meet again one of us will definitely appear older.

This has always puzzled me .... In my blog 'Space, Time & Einstein' the former is the conclusion drawn .... but it was written in 1929.

Can you help ??

Ta! greg